Drug safety information, including previous randomized trials of anti-PD-1 and anti-cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) antibodies, showed that patients treated with anti-PD-1 antibodies appeared to have more frequent and severe peripheral neuropathies compared to those in patients who received anti-CTLA-4 antibodies (1.59% vs. 0.69%; Fisher exact test, P < 0.001; three severe events vs. zero severe events). This evidence concerns the gene CTLA4 and peripheral neuropathy.